skin disease, any of the diseases or disorders that affect the human skin. They have a wide range of causes.

General features

Although most diseases affecting the skin originate in the layers of the skin, such abnormalities are also important factors in the diagnosis of a variety of internal diseases. There is some truth in the belief that the skin mirrors a person’s internal health. Often, the visibility and accessibility of skin make it the first organ of the body to show detectable signs of underlying disease. Abnormalities of the skin frequently suggest metabolic, malignant, and glandular diseases.